Cell change method, terminal, and network device

ABSTRACT

The present disclosure discloses a cell change method, a terminal, and a network device. By implementing this application, a problem that a receiving success rate of the change command cannot be improved when the another intra-frequency measurement event except the event 1D is triggered can be resolved.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/064,409, filed on Mar. 8, 2016, which is is a continuation ofInternational Patent Application No. PCT/CN2014/072647, filed on Feb.27, 2014, which claims priorities to International Patent ApplicationNo. PCT/CN2013/083132, filed on Sep. 9, 2013, All of the afore-mentionedpatent applications are hereby incorporated by reference in theirentireties.

TECHNICAL FIELD

Embodiments of the present disclosure relate to the field of wirelesscommunications technologies, and in particular, to a cell change method,and further to a terminal and a network device.

BACKGROUND

In a current communications system, to increase wireless resourceutilization and a network capacity of an entire system, a terminal maybe handed over among multiple cells. When communication quality of aserving cell becomes increasingly poor, a network may control theserving cell to send a change command to the terminal, so that theterminal is handed over to another cell with the best communicationquality in an active set. The active set refers to a set of cells towhich a terminal establishes a connection. Data transmission between auser and a network is performed by using a cell in the active set.

However, because the communication quality of the serving cell isalready extremely poor, when the serving cell sends the change commandto the terminal, the terminal may not receive the change command, whichcauses a small transmission success rate of the change command. Toimprove this situation, a better approach at present is to use all cellsexcept the serving cell in the active set as preconfigured cells, and aresource of a cell that serves as a serving cell is configured inadvance for the terminal, where the preconfigured resource may include atype of a serving cell change completion message, a transactionidentifier used by a serving cell completion message, indicationinformation of whether serving cell change resets a media access control(MAC) layer entity, an identifier, of a user equipment (UE) in apreconfigured cell, configuration information of a preconfiguredhigh-speed downlink shared channel (HS-DSCH) serving cell, andconfiguration information of an enhanced dedicated channel (E-DCH)serving cell, where the configuration information of the HS-DSCH servingcell refers to information about a resource, such as a channel, used bythe UE after the preconfigured cell becomes a serving cell, and theconfiguration information of the E-DCH serving cell refers toinformation about a resource, such as a channel, used by the UE afterthe preconfigured cell becomes a serving cell. Afterwards, cell changeis triggered according to an event 1D in intra-frequency measurementcontrol, and when the preconfigured cell triggers the event 1D, thenetwork controls this preconfigured cell to send a change command to theterminal, and the terminal completes a serving cell change processaccording to the change command. This process is also referred to as“enhanced serving cell change”. For example, in US2011/0014917A1,improved configuration of HS-DSCH serving cell change is disclosed, andin this configuration, when a neighboring cell whose pilot signalstrength is stronger than that of a current serving cell is detected(equivalent to triggering the event 1D), a change command is sent to theterminal by using this neighboring cell with stronger pilot signalstrength.

In the prior art, only the event 1D is considered when enhanced servingcell change is performed, but a non-event 1D in the intra-frequencymeasurement control is not considered, and the non-event 1D includes anevent 1A, an event 1B, an event 1C, an event 1E, and an event 1F. If theserving cell or another cell triggers the event 1B, 1C, or 1F, there aretwo problems in the prior art: 1. The network cannot determine whetherthe terminal needs to perform serving cell change. 2. Even if thenetwork can determine that the terminal needs to perform serving cellchange, the network cannot determine cell information of a target cellfor the serving cell change, because there may be at least one cell thatis stronger than the serving cell in the active set. Therefore, when thenon-event 1D is triggered, if the network determines that serving cellchange needs to be performed, the network still controls the servingcell to send a change command, which still causes a small transmissionsuccess rate of the change command.

A definition of each event in the intra-frequency measurement control isas follows:

Event 1A: Pilot signal strength of a cell that does not belong to theactive set increases, and a signal measurement value of a target cellenters a reporting range of relative active set quality.

Event 1B: Pilot signal strength of a cell in the active set reduces, anda signal measurement value of a target cell leaves a reporting range ofrelative active set quality.

Event 1C: Pilot signal strength of a cell outside the active set isgreater than pilot signal strength of the poorest cell in the activeset.

Event 1D: Pilot signal strength of a cell (not a serving cell) in theactive set is greater than pilot signal strength of a current servingcell.

Event 1E: Pilot signal strength of a cell exceeds an absolute threshold.Event 1F: Pilot signal strength of a cell is lower than an absolutethreshold.

SUMMARY

To resolve the foregoing technical problem, the present disclosureprovides a cell change method, a terminal, and a network device, whichcan resolve a problem that a transmission success rate of a changecommand cannot be improved when another intra-frequency measurementevent except an event 1D is triggered.

A first aspect of the present disclosure provides a cell change method,where the change method includes: receiving, by a terminal, ameasurement control message sent from a network device, and measuring ato-be-measured cell indicated in the measurement control message, toobtain a signal measurement value of each cell, where the to-be-measuredcell includes a candidate cell in an active set, there is at least onecandidate cell, and the candidate cell preconfigures a resource for theterminal; if the terminal determines, according to the signalmeasurement value of each cell, that any cell triggers an event 1D,determining the candidate cell that triggers the event 1D as a targetcell, reporting a measurement report to the network device, andmonitoring the target cell, so that the network device determines,according to the measurement report, the candidate cell that triggersthe event 1D as the target cell and controls the target cell to send achange command to the terminal; if the terminal determines, according tothe signal measurement value of each cell, that any cell triggersanother intra-frequency measurement event except the event 1D,selecting, according to a preset rule, a specified cell from a candidatecell whose signal measurement value is greater than that of a servingcell, reporting a measurement report to the network device, andmonitoring the specified cell, so that the network device determines,according to the measurement report, a target cell from the candidatecell whose signal measurement value is greater than that of the servingcell, and controls the target cell to send a change command to theterminal; and receiving, by the terminal, the change command, and usinga resource of the target cell to perform serving cell change in thetarget cell according to the change command, where there is onespecified cell or multiple specified cells, and the target cell is thespecified cell or one of the specified cells.

With reference to the first aspect, in a first possible implementationmanner of the first aspect, there is one specified cell, and themeasurement report includes cell information of the specified cell, sothat the network device determines the specified cell as the target cellaccording to the cell information of the specified cell.

With reference to the first aspect, in a second possible implementationmanner of the first aspect, there is one specified cell, and themeasurement report includes the signal measurement value of each cell,so that the network device determines, according to the preset rule, thetarget cell from the candidate cell whose signal measurement value isgreater than that of the serving cell.

With reference to the first aspect, in a third possible implementationmanner of the first aspect, there are at least two specified cells, andthe measurement report includes signal measurement values of the atleast two specified cells, so that the network device determines thetarget cell from the at least two specified cells.

With reference to any one of the first to the third possibleimplementation manners of the first aspect, in a fourth possibleimplementation manner of the first aspect, the measurement reportfurther includes a change request, so that the network devicedetermines, according to the change request, whether to control thetarget cell to send the change command to the terminal.

With reference to any one of the first to the third possibleimplementation manners of the first aspect, in a fifth possibleimplementation manner of the first aspect, the preset rule requires thatthe specified cell is a candidate cell with a largest signal measurementvalue or a candidate cell that has been in the active set for a longesttime.

With reference to the fifth possible implementation manner of the firstaspect, in a sixth possible implementation manner of the first aspect,if there are at least two candidate cells with a largest signalmeasurement value, the preset rule requires that the specified cell is acandidate cell that is listed in a preset location of the measurementreport and has a largest signal measurement value.

With reference to the sixth possible implementation manner of the firstaspect, in a seventh possible implementation manner of the first aspect,the preset rule requires that the specified cell is a candidate cellthat is the first one or last one listed in the measurement report andhas a largest signal measurement value.

With reference to the first aspect, in an eighth possible implementationmanner of the first aspect, if the terminal determines, according to thesignal measurement value of each cell, that any cell triggers theanother intra-frequency measurement event except the event 1D,constructing a trigger identifier of the event 1D in the measurementreport, so that the network device determines, according to the triggeridentifier, that the specified cell triggers the event 1D.

With reference to the first aspect, in a ninth possible implementationmanner of the first aspect, while or before the reporting a measurementreport to the network device, the change method further includes:reporting, by the terminal, capability information to the networkdevice, so that the network device determines, according to thecapability information, whether the terminal supports the cell change orpreconfiguration of a resource by the target cell when any cell triggersthe another intra-frequency measurement event except the event 1D.

With reference to the first aspect, in a tenth possible implementationmanner of the first aspect, the receiving, by the terminal, the changecommand from the target cell, and using the resource of the target cellto perform serving cell change in the target cell according to thechange command includes: determining, by the terminal, whether thechange command is received within a preset time; and if the changecommand is received within the preset time, using the resource of thetarget cell to perform serving cell change in the target cell accordingto the change command.

With reference to the tenth possible implementation manner of the firstaspect, in an eleventh possible implementation manner of the firstaspect, the receiving, by the terminal, the change command from thetarget cell, and using the resource of the target cell to performserving cell change in the target cell according to the change commandfurther includes: if the change command is not received within thepreset time, stopping, by the terminal, monitoring the specified cell.

With reference to the tenth possible implementation manner of the firstmanner, in a twelfth possible implementation manner of the first aspect,before receiving the change command, the change method further includes:if the terminal determines, within the preset time, that any celltriggers an intra-frequency measurement event, reporting, by theterminal, a measurement report to the network device.

With reference to the first aspect, in a thirteenth possibleimplementation manner of the first aspect, the change method furtherincludes: receiving, by the terminal, an active set update message fromthe network device, and deleting, from the active set according to theactive set update message, the serving cell before the change.

A second aspect of the present disclosure provides a cell change method,where the change method includes: generating, by a network device, ameasurement control message, and sending the measurement control messageto a terminal, so that the terminal measures a to-be-measured cellindicated in the measurement control message, to obtain a signalmeasurement value of each cell, where the to-be-measured cell includes acandidate cell in an active set, there is at least one candidate cell,and the candidate cell preconfigures a resource for the terminal;receiving, by the network device, a measurement report reported by theterminal; if the measurement report is generated after the terminaldetermines, according to the signal measurement value of each cell, thatany candidate cell triggers an event 1D, determining, by the networkdevice according to the measurement report, the candidate cell thattriggers the event 1D as a target cell, and controlling the target cellto send a change command to the terminal, so that the terminal uses aresource of the target cell to perform serving cell change in the targetcell according to the change command; and if the measurement report isgenerated after the terminal determines, according to the signalmeasurement value of each cell, that any cell triggers anotherintra-frequency measurement event except the event 1D, determining, bythe network device according to the measurement value, a target cellfrom a candidate cell whose signal measurement value is greater thanthat of a serving cell, and controlling the target cell to send a changecommand to the terminal, so that the terminal uses a resource of thetarget cell to perform serving cell change in the target cell accordingto the change command.

With reference to the second aspect, in a first possible implementationmanner of the second aspect, while or before the reporting, by thenetwork device, a measurement report reported by the terminal, thechange method further includes: receiving, by the network device,capability information reported by the terminal; determining, by thenetwork device according to the capability information, whether theterminal supports the serving cell change or preconfiguration of aresource by the target cell when any cell triggers the anotherintra-frequency measurement except the event 1D; if the network devicedetermines that the terminal supports the serving cell change or thepreconfiguration of a resource by the target cell, performing the stepof determining, by the network device according to the measurementreport, a target cell from a candidate cell whose signal measurementvalue is greater than that of a serving cell.

With reference to the second aspect, in a second possible implementationmanner of the second aspect, the change method further includes: if thenetwork device receives, before controlling the target cell to send thechange command to the terminal, the measurement report reported by theterminal, determining, by the network device according to themeasurement report, a new target cell from the candidate cell whose thesignal measurement value is greater than that of the serving cell, andcontrolling the new target cell to send a change command to theterminal.

With reference to the second aspect, in a third possible implementationmanner of the second aspect, the change method further includes:delivering, by the network device, an active set update message to theterminal, so that the terminal deletes, from an active set according tothe active set update message, the serving cell before the change.

A third aspect of the present disclosure provides a terminal, where theterminal includes a receiving module, a measuring module, a monitoringmodule, a reporting module, and a changing module, where the receivingmodule is configured to receive a measurement control message sent froma network device; the measuring module is configured to: measure ato-be-measured cell indicated in the measurement control message, toobtain a signal measurement value of each cell, and determine, accordingto the signal measurement value of each cell, whether any candidate celltriggers an event 1D or whether any cell triggers anotherintra-frequency measurement event except the event 1D, where theto-be-measured cell includes a candidate cell in an active set, there isat least one candidate cell, and the candidate cell preconfigures aresource for the terminal; the monitoring module is configured to: whenthe measuring module determines that any candidate cell triggers theevent 1D, monitor the candidate cell that triggers the event 1D, andconfigured to: when the measuring module determines that any celltriggers the another intra-frequency measurement event except the event1D, select, according to a preset rule, a specified cell from acandidate cell whose signal measurement value is greater than that of aserving cell, and monitor the specified cell; the reporting module isconfigured to: when the measuring module determines that any candidatecell triggers the event 1D, report a measurement report to the networkdevice, so that the network device determines, according to themeasurement report, the candidate cell that triggers the event 1D as atarget cell and controls the target cell to send a change command to theterminal, and configured to: when the measuring module determines thatany cell triggers the another intra-frequency measurement event exceptthe event 1D, report a measurement report to the network device, so thatthe network device determines, according to the measurement report, atarget cell from the candidate cell whose signal measurement value isgreater than that of the serving cell and controls the target cell tosend a change command to the terminal; the receiving module is furtherconfigured to receive the change command from the target cell; thechanging module is configured to use a resource of the target cell toperform serving cell change in the target cell according to the changecommand, where there is one specified cell or multiple specified cells,and the target cell is the specified cell or one of the specified cells.

With reference to the third aspect, in a first possible implementationmanner of the third aspect, there is one specified cell, and themeasurement report includes cell information of the specified cell, sothat the network device determines the specified cell as the target cellaccording to the cell information of the specified cell.

With reference to the third aspect, in a second possible implementationmanner of the third aspect, there is one specified cell, and themeasurement report includes the signal measurement value of each cell,so that the network device determines, according to the preset rule, thetarget cell from the candidate cell whose signal measurement value isgreater than that of the serving cell.

With reference to the third aspect, in a third possible implementationmanner of the third aspect, there are at least two specified cells, andthe measurement report includes signal measurement values of the atleast two specified cells, so that the network device determines thetarget cell from the at least two specified cells.

With reference to any one of the first to the third possibleimplementation manners of the third aspect, in a fourth possibleimplementation manner of the third aspect, the measurement reportfurther includes a change request, so that the network devicedetermines, according to the change request, whether to control thetarget cell to send the change command to the terminal.

With reference to any one of the first to the third possibleimplementation manners of the third aspect, in a fifth possibleimplementation manner of the third aspect, the preset rule requires thatthe specified cell is a candidate cell with a largest signal measurementvalue or a candidate cell that has been in the active set for a longesttime.

With reference to the fifth possible implementation manner of the thirdaspect, in a sixth possible implementation manner of the third aspect,if there are at least two candidate cells with a largest signalmeasurement value, the preset rule requires that the specified cell is acandidate cell that is listed in a preset location of the measurementreport and has a largest signal measurement value.

With reference to the sixth possible implementation manner of the thirdaspect, in a seventh possible implementation manner of the third aspect,the preset rule requires that the specified cell is a candidate cellthat is the first one or last one listed in the measurement report andhas a largest signal measurement value.

With reference to the third aspect, in an eighth possible implementationmanner of the third aspect, if the measuring module determines that anycell triggers the another intra-frequency measurement event except theevent 1D, the reporting module is further configured to construct atrigger identifier of the event 1D in the measurement report, so thatthe network device determines, according to the trigger identifier, thatthe specified cell triggers the event 1D.

With reference to the third aspect, in a ninth possible implementationmanner of the third aspect, the reporting module is further configuredto: while or before reporting the measurement report to the networkdevice, report capability information to the network device, so that thenetwork device determines, according to the capability information,whether the terminal supports the serving cell change orpreconfiguration of a resource by the target cell when any cell triggersthe another intra-frequency measurement event except the event 1D.

With reference to the third aspect, in a tenth possible implementationmanner of the third aspect, the changing module is configured to:determine whether the change command is received within a preset time,and when determining that the change command is received within thepreset time, use the resource of the target cell to perform serving cellchange in the target cell according to the change command.

With reference to the tenth possible implementation in the third aspect,in an eleventh possible implementation manner of the third aspect, themonitoring module is further configured to stop monitoring the specifiedcell when the changing module determines that the change command is notreceived within the preset time.

With reference to the tenth possible implementation manner of the thirdaspect, in a twelfth possible implementation manner of the third aspect,if before the changing module receives the change command, the measuringmodule determines, within the preset time, that any cell triggers anintra-frequency measurement event, the reporting module is furtherconfigured to report a measurement report to the network device.

With reference to the third aspect, in a thirteenth possibleimplementation manner of the third aspect, the receiving module isfurther configured to receive an active set update message from thenetwork device; the terminal further includes an updating module,configured to delete, from the active set according to the active setupdate message, the serving cell before the change.

A fourth aspect of the present disclosure provides a network device,where the network device includes a sending module, a receiving module,and a processing module, where the sending module is configured to senda measurement control message to a terminal, so that the terminalmeasures a to-be-measured cell indicated in the measurement controlmessage, to obtain a signal measurement value of each cell, where theto-be-measured cell includes a candidate cell in an active set, there isat least one candidate cell, and the candidate cell preconfigures aresource for the terminal; the receiving module is configured to receivea measurement report reported by the terminal; if the measurement reportis generated after the terminal determines, according to the signalmeasurement value of each cell, that any candidate cell triggers anevent 1D, the processing module is configured to: determine, accordingto the measurement report, the candidate cell that triggers the event 1Das a target cell, and control the target cell to send a change commandto the terminal, so that the terminal uses a resource of the target cellto perform serving cell change in the target cell according to thechange command; and if the measurement report is generated after theterminal determines, according to the signal measurement value of eachcell, that any cell triggers another intra-frequency measurement eventexcept the event 1D, the processing module is configured to: determine,according to the measurement report, a target cell from a candidate cellwhose signal measurement value is greater than that of a serving cell,and control the target cell to send a change command to the terminal, sothat the terminal uses a resource of the target cell to perform servingcell change in the target cell according to the change command.

With reference to the fourth aspect, in a first possible implementationmanner of the fourth aspect, the network device further includes adetermining module, where the receiving module is configured to: whileor before receiving the measurement report reported by the terminal,receive capability information reported by the terminal; the determiningmodule is configured to determine, according to the capabilityinformation, whether the terminal supports the serving cell change orpreconfiguration of a resource by the target cell when any cell triggersthe another intra-frequency measurement except the event 1D; and theprocessing module is further configured to: when the determining moduledetermines that the terminal supports the serving cell change or thepreconfiguration of a resource by the target cell, determine, accordingto the measurement report, the target cell from the candidate cell whosesignal measurement value is greater than that of the serving cell.

With reference to the fourth aspect, in a second possible implementationmanner of the fourth aspect, if the receiving module receives, beforethe processing module controls the target cell to send the changecommand to the terminal, the measurement report reported by theterminal, the processing module is further configured to: receive themeasurement report again from the receiving module, determine, accordingto the measurement report, a new target cell from the candidate cellwhose signal measurement value is greater than that of the serving cell,and control the new target cell to send a change command to theterminal.

With reference to the fourth aspect, in a third possible implementationmanner of the fourth aspect, the network device further includes acommand updating module, and the command updating module is configuredto generate an active set update message, and the sending module isconfigured to deliver the active set update message to the terminal, sothat the terminal deletes, from the active set according to the activeset update message, the serving cell before the change.

A fifth aspect of the present disclosure provides a terminal, where theterminal includes a processor, a receiver, and a transmitter, where thereceiver is configured to receive a measurement control message sentfrom a network device; the processor is configured to: measure ato-be-measured cell indicated in the measurement control message, toobtain a signal measurement value of each cell, and determine, accordingto the signal measurement value of each cell, whether any candidate celltriggers an event 1D or whether any cell triggers anotherintra-frequency measurement event except the event 1D, where theto-be-measured cell includes a candidate cell in an active set, there isat least one candidate cell, and the candidate cell preconfigures aresource for the terminal; the processor is further configured to: whendetermining that any candidate cell triggers the event 1D, monitor acandidate cell that triggers the event 1D, and configured to: whendetermining that any cell triggers the another intra-frequencymeasurement event except the event 1D, select, according to a presetrule, a specified cell from a candidate cell whose signal measurementvalue is greater than that of a serving cell, and monitor the specifiedcell; the transmitter is configured to: when the processor determinesthat any candidate cell triggers the event 1D, report a measurementreport to the network device, so that the network device determines,according to the measurement report, the candidate cell that triggersthe event 1D as a target cell and controls the target cell to send achange command to the terminal, and configured to: when the processordetermines that any cell triggers the another intra-frequencymeasurement event except the event 1D, report a measurement report tothe network device, so that the network device determines, according tothe measurement report, a target cell from the candidate cell whosesignal measurement value is greater than that of the serving cell andcontrols the target cell to send a change command to the terminal; thereceiver is further configured to receive the change command from thetarget cell; and the processor is configured to use a resource of thetarget cell to perform serving cell change in the target cell accordingto the change command, where there is one specified cell or multiplespecified cells, and the target cell is the specified cell or one of thespecified cells.

With reference to the fifth aspect, in a first possible implementationmanner of the fifth aspect, there is one specified cell, and themeasurement report includes cell information of the specified cell, sothat the network device determines the specified cell as the target cellaccording to the cell information of the specified cell.

With reference to the fifth aspect, in a second possible implementationmanner of the fifth aspect, there is one specified cell, and themeasurement report includes the signal measurement value of each cell,so that the network device determines, according to the preset rule, thetarget cell from the candidate cell whose signal measurement value isgreater than that of the serving cell.

With reference to the fifth aspect, in a third possible implementationmanner of the fifth aspect, there are at least two specified cells, andthe measurement report includes signal measurement values of the atleast two specified cells, so that the network device determines thetarget cell from the at least two specified cells.

With reference to any one of the first to the third possibleimplementation manners of the fifth aspect, in a fourth possibleimplementation manner of the fifth aspect, the measurement reportfurther includes a change request, so that the network devicedetermines, according to the change request, whether to control thetarget cell to send the change command to the terminal.

With reference to any one of the first to the third possibleimplementation manners of the fifth aspect, in a fifth possibleimplementation manner of the fifth aspect, the preset rule requires thatthe specified cell is a candidate cell with a largest signal measurementvalue or a candidate cell that has been in the active set for a longesttime.

With reference to the fifth possible implementation manner of the thirdaspect, in a sixth possible implementation manner of the fifth aspect,if there are at least two candidate cells with a largest signalmeasurement value, the preset rule requires that the specified cell is acandidate cell that is listed in a preset location of the measurementreport and has a largest signal measurement value

With reference to the sixth possible implementation manner of the thirdaspect, in a seventh possible implementation manner of the fifth aspect,the preset rule requires that the specified cell is a candidate cellthat is the first one or last one listed in the measurement report andhas a largest signal measurement value.

With reference to the fifth aspect, in an eighth possible implementationmanner of the fifth aspect, if the processor determines that any celltriggers the another intra-frequency measurement event except the event1D, the transmitter is further configured to construct a triggeridentifier of the event 1D in the measurement report, so that thenetwork device determines, according to the trigger identifier, that thespecified cell triggers the event 1D.

With reference to the fifth aspect, in a ninth possible implementationmanner of the fifth aspect, the transmitter is further configured to:while or before reporting the measurement report to the network device,report capability information to the network device, so that the networkdevice determines, according to the capability information, whether theterminal supports the cell change or preconfiguration of a resource bythe target cell when any cell triggers the another intra-frequencymeasurement event except the event 1D.

With reference to the fifth aspect, in a tenth possible implementationmanner of the fifth aspect, the processor is configured to: determinewhether the change command is received within a preset time, and whendetermining that the change command is received within the preset time,use the resource of the target cell to perform serving cell change inthe target cell according to the change command.

With reference to the tenth possible implementation manner of the fifthaspect, in an eleventh possible implementation manner of the fifthaspect, the processor is further configured to stop monitoring thespecified cell when the receiver determines that the change command isnot received within the preset time.

With reference to the tenth possible implementation manner of the fifthaspect, in a twelfth possible implementation manner of the fifth aspect,if before the receiver receives the change command, the processordetermines, within the preset time, that any cell triggers theintra-frequency measurement event, the transmitter is further configuredto report a measurement report to the network device.

With reference to the fifth aspect, in a thirteenth possibleimplementation manner of the fifth aspect, the receiver is furtherconfigured to receive an active set update message from the networkdevice, and the processor is further configured to delete, from theactive set according to the active set update message, the serving cellbefore the change.

A sixth aspect of the present disclosure provides a network device,where the network device includes a transmitter, a receiver, and aprocessor, where the transmitter is configured to send a measurementcontrol message to a terminal, so that the terminal measures ato-be-measured cell indicated in the measurement control message, toobtain a signal measurement value of each cell, where the to-be-measuredcell includes a candidate cell in an active set, there is at least onecandidate cell, and the candidate cell preconfigures a resource for theterminal; the receiver is configured to receive a measurement reportreported by the terminal; if the measurement report is generated afterthe terminal determines, according to the signal measurement value ofeach cell, that any candidate cell triggers an event 1D, the processoris configured to: determine, according to the measurement report, thecandidate cell that triggers the event 1D as a target cell, and controlthe target cell to send a change command to the terminal, so that theterminal uses a resource of the target cell to perform serving cellchange in the target cell according to the change command; and if themeasurement report is generated after the terminal determines, accordingto the signal measurement value of each cell, that any cell triggersanother intra-frequency measurement event except the event 1D, theprocessor is configured to: determine, according to the measurementreport, a target cell from the candidate cell whose signal measurementvalue is greater than that of a serving cell, and control the targetcell to send a change command to the terminal, so that the terminal usesa resource of the target cell to perform serving cell change in thetarget cell according to the change command.

With reference to the sixth aspect, in a first possible implementationmanner of the sixth aspect, the receiver is further configured toreceive capability information reported by the terminal; the processoris further configured to determine, according to the capabilityinformation, whether the terminal supports the serving cell change orpreconfiguration of a resource by the target cell when any cell triggersthe another intra-frequency measurement event except the event 1D; andfurther configured to: when it is determined that the terminal supportsthe serving cell change or the preconfiguration of a resource by thetarget cell, according to the measurement report, the target cell fromthe candidate cell whose signal measurement value is greater than thatof the serving cell.

With reference to the sixth aspect, in a second possible implementationmanner of the sixth aspect, if the receiver receives, before theprocessor controls the target cell to send the change command to theterminal, the measurement report reported by the terminal, the processoris further configured to: receive the measurement report again from thereceiver, determine, according to the measurement report, a new targetcell from the candidate cell whose signal measurement value is greaterthan that of the serving cell, and control the new target cell to send achange command to the terminal.

With reference to the sixth aspect, in a third possible implementationmanner of the sixth aspect, the processor is further configured togenerate an active set update message, and the transmitter is furtherconfigured to deliver the active set update message to the terminal, sothat the terminal deletes, from the active set according to the activeset update message, the serving cell before the change.

In summary, according to the cell change method, the terminal, and thenetwork device of the present disclosure, when it is determined that anycell triggers another intra-frequency measurement event except an event1D, the terminal determines, according to a preset rule, a specifiedcell from a candidate cell whose signal measurement value is greaterthan that of a serving cell and monitors the specified cell; the networkdevice determines a target cell from the candidate cell whose signalmeasurement value is greater than that of the serving cell, the targetcell is the specified cell or one of specified cells, and the candidatecell preconfigures a resource for the terminal before any cell triggersanother intra-frequency measurement event except the event 1D, so thatthe terminal may receive a change command from the target cell, and usea resource of the target cell to perform serving cell change in thetarget cell according to the change command. Because a signalmeasurement value of the specified cell is greater than the signalmeasurement value of the serving cell, a transmission success rate ofthe change command can be significantly improved, thereby resolving aproblem that a transmission success rate of the change command cannot beimproved when the another intra-frequency measurement event except theevent 1D is triggered; in addition, because the target cell haspreconfigured the resource, signaling overheads can be reduced, so thatthe serving cell change process can be rapidly performed.

The foregoing explanation is merely an outline of a technical solutionof the present disclosure. To understand a technical means of thepresent disclosure more clearly, to implement the present disclosureaccording to content of the specifications, and to make the foregoingand other objectives, features, and advantages of the present disclosuremore apparent and understandable, exemplary embodiments are enumeratedin the following. With reference to the accompanying drawings,explanation is as follows.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic flowchart of a first embodiment of a cell changemethod according to the present disclosure;

FIG. 2 is a schematic flowchart of a second embodiment of a cell changemethod according to the present disclosure;

FIG. 3 is a schematic signaling diagram of an application scenario ofthe cell change method shown in FIG. 2;

FIG. 4 is a schematic flowchart of a third embodiment of a cell changemethod according to the present disclosure;

FIG. 5 is a schematic structural diagram of a first embodiment of aterminal according to the present disclosure;

FIG. 6 is a schematic structural diagram of a second embodiment of aterminal according to the present disclosure;

FIG. 7 is a schematic structural diagram of a first embodiment of anetwork device according to the present disclosure;

FIG. 8 is a schematic structural diagram of a third embodiment of aterminal according to the present disclosure; and

FIG. 9 is a schematic structural diagram of a second embodiment of anetwork device according to the present disclosure.

DESCRIPTION OF EMBODIMENTS

The following describes the technical solutions in the embodiments ofthe present disclosure with reference to the accompanying drawings inthe embodiments of the present disclosure. Apparently, the describedembodiments are merely some but not all of the embodiments of thepresent disclosure. All other embodiments obtained by a person ofordinary skill in the art based on the embodiments of the presentdisclosure without creative efforts shall fall within the protectionscope of the present disclosure.

FIG. 1 is a schematic flowchart of a first embodiment of a cell changemethod according to the present disclosure.

S11: A terminal receives a measurement control message sent from anetwork device, and measures a to-be-measured cell indicated in themeasurement control message, to obtain a signal measurement value ofeach cell, where the to-be-measured cell includes a candidate cell in anactive set, there is at least one candidate cell, and the candidate cellpreconfigures a resource for the terminal.

The signal measurement value may be an received signal code power (RSCP)value or an Ec/No (received energy per chip divided by the power densityin the band) value of pilot signal strength, or may be an accumulatedvalue of an RSCP value or an Ec/No value of pilot signal strength and acell individual offset (CIO) value. A pilot signal refers to a signalsent in a telecommunications network for a purpose of measurement ormonitoring. The active set includes a serving cell and a candidate cell,where the serving cell is a cell that provides a high speed downlinkshared channel (HS-DSCH) service or an enhanced dedicated channel(E-DCH) service for the terminal, and the candidate cell is a cell thatdoes not provide the HS-DSCH service or the E-DCH service for theterminal but establishes a link to the terminal, or a cell that providesthe HS-DSCH service or the E-DCH service for the terminal but serves asa coordinated cell of the serving cell. A cell outside the active setmay be a cell in a set such as a monitoring set or a detection set.

The resource preconfigured by the candidate cell includes at least achannel resource, an air interface resource, and the like. The activeset includes at least one candidate cell.

S12: If the terminal determines, according to the signal measurementvalue of each cell, that any candidate cell triggers an event 1D,determines the candidate cell that triggers the event 1D as a targetcell, reports a measurement report to the network device, and monitorsthe target cell, so that the network device determines, according to themeasurement report, the candidate cell that triggers the event 1D as thetarget cell, and controls the target cell to send a change command tothe terminal.

S13: If the terminal determines, according to the signal measurementvalue of each cell, that any cell triggers another intra-frequencymeasurement event except the event 1D, selects, according to a presetrule, a specified cell from a candidate cell whose signal measurementvalue is greater than that of a serving cell, reports a measurementreport to the network device, and monitors the specified cell, so thatthe network device determines, according to the measurement report, atarget cell from the candidate cell whose signal measurement value isgreater than that of the serving cell, and controls the target cell tosend a change command to the terminal.

The another intra-frequency measurement event except the event 1D is anon-event 1D. Because the specified cell is selected from the candidatecell whose signal measurement value is greater than that of the servingcell, regardless of whether the serving cell or the candidate celltriggers the non-event 1D, it indicates that the signal measurementvalue of the serving cell is not the largest.

For example, when the serving cell triggers an event 1B or an event 1F,it indicates that the signal measurement value of the serving cell isalready lower than a threshold and this situation is kept for a periodof time, for example, the terminal is increasingly far from the servingcell. For example, a threshold T and time t are given in the measurementcontrol message, where the threshold T may be a signal measurement valueof a candidate cell in the active set, or may be a preset signalmeasurement value. If the signal measurement value of the serving cellis lower than T and this situation is kept for time t1, a triggercondition for the event 1B or the event 1F is met, where a value oft isgenerally 640 ms. In addition, this event may indicate that the signalmeasurement value of the serving cell is at least a specified thresholdlower than a largest signal measurement value of a candidate cell in theactive set. If a candidate cell triggers the event 1B or 1F, itindicates that the signal measurement value of the serving cell isgreater than that of this candidate cell, but is still lower than thoseof some other candidate cells.

If the serving cell triggers an event 1C, it indicates that the servingcell is a cell that has a smallest signal measurement value in theactive set, and a signal measurement value of a cell outside the activeset is greater than the signal measurement value of the serving cell.This situation is kept for a period of time, and a value of this time is320 ms. If a candidate cell triggers the event 1C, it indicates thatthis candidate cell is a cell that has a smallest signal measurementvalue in the active set, but the serving cell in this case is not a cellthat has a largest signal measurement value in the active set.

In addition, when a candidate cell in the active set or a cell outsidethe active set triggers an event 1E, a situation in which the signalmeasurement value of the candidate cell is greater than that of theserving cell may also exist.

When a terminal triggers the non-event 1D, generally, a cell thattriggers the non-event 1D is not a target cell for serving cell change.For example, when the event 1B is triggered, a target cell that triggersthe event 1B is a cell to be deleted; when the event 1C is triggered, atarget cell that triggers the event 1C is a cell to be replaced. Inaddition, the target cell may not be a candidate cell whose signalmeasurement value is greater than that of the serving cell.

In this embodiment, preferably, the serving cell triggers the event 1B,1C, or 1F.

S14: The terminal receives the change command from the target cell, anduses a resource of the target cell to perform serving cell change in thetarget cell according to the change command, where there is onespecified cell or multiple specified cells, and the target cell is thespecified cell or one of the specified cells.

Because the target cell is the specified cell or one of the specifiedcells, the specified cell monitored by the terminal certainly includesthe target cell, so that the change command may be received from thetarget cell. The terminal cannot immediately receive the change commandafter reporting the measurement report, but monitors the target cellafter reporting the measurement report, to wait for the target cell tosend the change command. In this embodiment, the change command is sentat a physical layer. For example, the change command is a high speedshared control channel (HS-SCCH) Order.

When the terminal performs serving cell change, because the target cellhas preconfigured the resource for the terminal, the terminal does notneed to request the target cell to send information about the configuredresource, and only needs to receive the change command and rapidlycomplete the serving cell change.

In the cell change method provided in this embodiment of the presentdisclosure, a candidate cell in an active set preconfigures a resourcefor a terminal. If any cell triggers another intra-frequency measurementevent except an event 1D, the terminal determines a specified cell froma candidate cell whose signal measurement value is greater than that ofa serving cell, and monitors the specified cell; a network devicedetermines a target cell from the candidate cell whose signalmeasurement value is greater than that of the serving cell, and controlsthe target cell to send a change command. The target cell is thespecified cell or one of specified cells, a signal measurement value ofthe specified cell is greater than the signal measurement value of theserving cell, and the target cell has preconfigured a resource for theterminal, so that a problem that a transmission success rate of thechange command cannot be improved when the another intra-frequencymeasurement event except the event 1D is triggered can be resolved, andsignaling overheads can be reduced, and a serving cell change processcan be rapidly performed.

FIG. 2 is a schematic flowchart of a second embodiment of a cell changemethod according to the present disclosure.

S21: A terminal receives a measurement control message sent from anetwork device, and measures a to-be-measured cell indicated in themeasurement control message, to obtain a signal measurement value ofeach cell, where the to-be-measured cell includes a candidate cell in anactive set, there is at least one candidate cell, and the candidate cellpreconfigures a resource for the terminal.

For details about S21, refer to S11 in the first embodiment, and thedetails are not described herein again.

S22: If the terminal determines, according to the signal measurementvalue of each cell, that any candidate cell triggers an event 1D,determines the candidate cell that triggers the event 1D as a targetcell, reports a measurement report to the network device, and monitorsthe target cell, so that the network device determines, according to themeasurement report, the candidate cell that triggers the event 1D as thetarget cell, and controls the target cell to send a change command tothe terminal.

S23: If the terminal determines, according to the signal measurementvalue of each cell, that any cell triggers another intra-frequencymeasurement event except the event 1D, selects, according to a presetrule, a specified cell from a candidate cell whose signal measurementvalue is greater than that of a serving cell, reports a measurementreport to the network device, and monitors the specified cell, so thatthe network device determines, according to the measurement report, atarget cell from the candidate cell whose signal measurement value isgreater than that of the serving cell, and controls the target cell tosend a change command to the terminal.

In this embodiment, preferably, the serving cell triggers an event 1B,1C, or 1F. There are multiple implementation manners of determining, bythe network device, a target cell to which the serving cell is changed.Some examples are described in detail by reference to the followingsituations:

In a first situation, there is one specified cell. In this case, themeasurement report includes cell information of the specified cell, sothat the network device determines the specified cell as the target cellaccording to the cell information of the specified cell. That is, whenthe terminal determines the specified cell, the network device does notknow which candidate cell is determined as the specified cell by theterminal, and therefore the terminal needs to report, in the measurementreport, the cell information of the specified cell to the networkdevice. The cell information may be a scrambling code or a cellidentifier of the specified cell.

Another implementation manner of determining, by the terminal, thespecified cell according to the preset rule is to select any candidatecell whose signal measurement value is greater than that of the servingcell as the specified cell.

In a second situation, there is one specified cell. In this case, themeasurement report includes the signal measurement value of each cell,so that the network device determines, according to the preset rule, thetarget cell from the candidate cell whose signal measurement value isgreater than that of the serving cell. Because the terminal obtains thesignal measurement value of each cell, the terminal can know whichcandidate cell has greater signal measurement value than that of theserving cell, so that the specified cell may be determined according tothe preset rule.

Another implementation manner of determining, by the terminal, thespecified cell according to the preset rule is to select a cell whosesignal measurement value is greater than that of the serving cell andhas a largest measurement value among the candidate cell as thespecified cell. Similarly, a network side determines the target cellaccording to this rule, which can ensure that a specified celldetermined by the terminal and a target cell determined by the networkdevice are consistent.

In a third situation, there are at least two specified cells. In thiscase, the measurement report also includes a signal measurement value ofeach specified cell, so that the network device determines the targetcell from the at least two specified cells. The target cell determinedby the network device may be any one of the specified cells. Becausesignal measurement values of the specified cells are greater than thesignal measurement value of the serving cell, a signal measurement valueof the target cell is certainly greater than the signal measurementvalue of the serving cell. Because the target cell is one of thespecified cells, the terminal must monitor all specified cells, andcertainly, the terminal may also monitor the target cell.

In the foregoing second and third situations, the measurement report mayalso include a comparison result of the signal measurement value. Forexample, in the second situation, the measurement report includes onlythe comparison result of the signal measurement value of each cell, butdoes not carry the signal measurement value of each cell. For example,the comparison result is a descending order relationship of all cellsaccording to the signal measurement value, and then, the network devicecan directly know, from the comparison result, which candidate cell hasa greater signal measurement value than that of the serving cell, andwhich candidate cell has a largest signal measurement value.

In the foregoing three situations, the preset rule may require that thespecified cell is a candidate cell that has a largest signal measurementvalue among the candidate cell whose signal measurement value is greaterthan that of the serving cell, a candidate cell that has been in theactive set for a longest time among the candidate cell whose signalmeasurement value is greater than that of the serving cell, or acandidate cell that is the first to join the active set among thecandidate cell whose signal measurement value is greater than that ofthe serving cell. If there are at least two cells in the active set thathave a same largest signal measurement value, the preset rule mayrequire that the specified cell is determined according to a cellsequence in the measurement report. For example, it is stipulated thatan Nth candidate cell that has a largest signal measurement value in ameasurement result list is the specified cell, where 1≤N≤m, m is aquantity of cells in the active set. Preferably, the specified cell maybe a first candidate cell that has a largest signal measurement value,and a measurement result of this candidate cell is the first one or lastone listed in the measurement result list. Regardless of how the presetrule changes, the signal measurement value of the specified cell must begreater than the signal measurement value of the serving cell, and thespecified cell determined by the terminal includes at least the targetcell determined by the network. Because the measurement report includesthe signal measurement value of each cell, the network device maydetermine the target cell according to a preset rule that is the same asthat of the terminal.

In this embodiment, while or before the terminal reports the measurementreport to the network device, the terminal further reports capabilityinformation to the network device, so that the network devicedetermines, according to the capability information, whether theterminal supports serving cell change or preconfiguration of a resourceby the target cell, that is, “enhanced serving cell change”, when anycell triggers the another intra-frequency measurement event except theevent 1D. If the terminal does not support the serving cell change orthe preconfiguration of a resource by the target cell, the networkdevice may not perform a next operation after receiving the measurementreport.

In this embodiment, after the terminal sends a measurement report of anon-event 1D, the network device may learn, by using content of themeasurement report, that the terminal requests to perform serving cellchange. The content may be one of the following:

1. The serving cell triggers the non-event 1D.

2. The signal measurement value of the serving cell is the smallest inthe active set.

3. There is no cell information of a candidate cell that triggers thenon-event 1D, or cell information of the specified cell.

4. A serving cell change request, where the change request is used bythe network device to determine whether to control the target cell tosend the change command to the terminal.

5. Capability information of supporting enhanced serving cell change.

6. An activation time offset used to calculate duration of monitoringactivation time of the specified cell.

7. Duration used to indicate monitoring of activation time of thespecified cell.

8. Capability information of supporting the preconfiguration of aresource by the target cell.

In this embodiment, when the terminal determines, according to thesignal measurement value of each cell, that any cell triggers theanother intra-frequency measurement event except the event 1D, a specialevent 1D may be constructed, that is, constructing, in the measurementreport, a trigger identifier of the event 1D, and this triggeridentifier is used by the network device to determine that the specifiedcell triggers the event 1D. The special event 1D refers to that thespecified cell actually does not trigger the event 1D, and the event 1Dis fabricated by the terminal. Alternatively, the trigger identifier maybe a special value that is mutually agreed on by the terminal and thenetwork device, or may be a value of a measurement identifier, deliveredby the network device, of the event 1D. After determining, according tothe trigger identifier, that the specified cell triggers the event 1D,the network device may perform an enhanced serving cell change process.

S24: The terminal determines whether the change command is receivedwithin a preset time; if the change command is received within thepreset time, performs S24; if the change command is not received withinthe preset time, performs S27.

Because the target cell is the specified cell monitored by the terminal,when the target cell sends the change command, the change command can bereceived by the terminal.

The terminal may carry the activation time offset when reporting themeasurement report, and the preset time is a current connection framenumber (CFN) when reporting the measurement report plus the activationtime offset. In wireless communication, especially in an air interfacesynchronization configuration instruction, the network device generallyneeds to add the activation time offset to signaling, and the activationtime offset specifies a frame number that causes changed configurationof the terminal to take effect. Herein, the activation time offsetindicates duration in which the terminal monitors the specified cell.

If the measurement report does not carry the activation time offset, theterminal may determine, by timing with a timer, whether the preset timeis exceeded.

S25: Use a resource of the target cell to perform serving cell change inthe target cell according to the change command.

When the terminal performs the serving cell change, because the targetcell has preconfigured the resource for the terminal, the terminal doesnot need to request the target cell to send information about theconfigured resource, and only needs to receive the change command andrapidly complete the serving cell change, which reduces signalingoverheads. If the terminal monitors multiple specified cells, monitoringof all specified cells may be stopped when the terminal receives thechange command from a specified cell, and in this case, the specifiedcell that sends the change command is the target cell.

S26: The terminal sends a change completion message in response to thechange command to the network device, so that the network devicedetermines, according to the change completion message, that theterminal completes the serving cell change.

When the candidate cell preconfigures the resource for the terminal, theterminal may be notified of cell information of the candidate cell thatpreconfigures the resource. For example, the network device may send alist of preconfigured information to the terminal, and the list ofpreconfigured information may include at least one piece of thefollowing information: a type of a message that is used to indicatechange completion and is sent to the target cell after the serving cellchange is completed, a transaction identifier used when the serving cellchange is completed, indication information of whether a MAC layer isreset when the serving cell change is completed, an air interfaceidentifier used in a serving cell change process, related configurationinformation of an HS-DSCH resource when the serving cell provides anHS-DSCH service for the terminal, and related configuration informationof an E-DCH resource when the serving cell provides an E-DCH service forthe terminal. The change completion message is obtained from the messagetype in the foregoing list.

S27: The terminal receives an active set update message from the networkdevice, and deletes, from the active set according to the active setupdate message, the serving cell before the change.

If the original serving cell, that is, the serving cell before theserving cell change is performed, triggers the event 1B, active setupdate information is used to instruct the terminal to delete theoriginal serving cell from the active set. If the original serving celltriggers the event 1C, the active set update information is used toinstruct the terminal to delete the original serving cell from theactive set, and add, to the active set, a cell that is outside theactive set and whose signal measurement value is greater than that ofthe original serving cell, that is, a cell that triggers the event 1C.

Further, if a cell outside the active set triggers the event 1E, and acapacity of the active set does not reach an upper limit, the terminalmay add this cell to the active set according to the active set updatemessage. If the capacity of the active set has reached the upper limit,the terminal may delete, according to the active set update message, acandidate cell that has a smallest signal measurement value in theactive set, and add this cell outside the active set to the active set.It should be noted that, because the terminal has completed the servingcell change, the original serving cell becomes the candidate cell, andtherefore, the candidate cell that has a smallest signal measurementvalue may be the primary serving cell.

S28: The terminal stops monitoring the specified cell.

S29: If the terminal determines, within the preset time, that any celltriggers an intra-frequency measurement event, it performs the step ofreporting, by the terminal, a measurement report to the network device.

Generally, the terminal periodically performs intra-frequencymeasurement control. If the terminal determines that any cell triggersthe intra-frequency measurement event, that is, any cell triggers anyevent of the event 1A, the event 1B, the event 1C, the event 1D, theevent 1E, and the event IF before the change command is received andbefore the preset time is exceeded, the terminal reports the measurementreport to the network device and recalculates time for monitoring thespecified cell, so that the network device redetermines a target cellaccording to the measurement report.

There is a sequence of triggering an event by the terminal. For example,after the terminal sends a measurement report of the event 1B, if achange command is not received and the event 1D is triggered, ameasurement report of the event 1D may be sent to the network device.

In another embodiment, after the terminal sends a measurement report forthe first time, and when the terminal determines, within a preset timefor waiting to receive a change command, that any cell triggers anintra-frequency measurement event, the terminal may not report themeasurement report to the network device, or may not recalculate timefor monitoring a specified cell, but continues to wait to receive thechange command.

Further, corresponding specified cells determined when the terminalsends two measurement reports in succession are different. For example,the specified cells determined by the terminal twice in succession arecandidate cells that have a largest signal measurement value, but thecandidate cells that have a largest signal measurement value and aredetermined twice in succession are not a same candidate cell. Then, theterminal may report a measurement report again to the network device, sothat the network device redetermines a target cell according to themeasurement report. A manner for determining the target cell is notdescribed in detail herein.

Further, if corresponding specified cells determined when twomeasurement reports are sent in succession by the terminal areinconsistent, the terminal may at the same time monitor the specifiedcells that are determined twice in succession, and the network devicemay certainly select one specified cell, as the target cell, from thespecified cells determined twice in succession.

FIG. 3 is a schematic signaling diagram of an application scenario ofthe cell change method shown in FIG. 2. In this application scenario,schematically, an active set includes only two candidate cells, and asignaling process is as follows:

S301: A network device controls the two candidate cells to preconfigurea resource for a terminal.

S302: The network device sends a list of preconfigured information aboutthe two candidate cells to the terminal.

The list of preconfigured information indicates that the two candidatecells have already completed the preconfiguration of the resource forthe terminal.

S303: The network device sends a measurement control message to theterminal.

A to-be-measured cell is indicated in the measurement control message,where the to-be-measured cell includes a candidate cell in the activeset, and may further include a cell outside the active set, and thecandidate cell preconfigures a resource for the terminal.

S304: The terminal measures a signal measurement value of theto-be-measured cell, and determines that any cell triggers an event 1C.

The event 1C indicates that a signal measurement value of a serving cellis lower than signal measurement values of the two candidate cells, andis further lower than a signal measurement value of a cell outside theactive set.

S305: The terminal selects a candidate cell that has a largest signalmeasurement value as a specified cell, and sends a measurement report tothe network and monitors the specified cell.

The measurement report indicates that the terminal requests to performserving cell change. For example, the measurement report includes arequest for enhanced serving cell change, cell information of thespecified cell, capability information of supporting enhanced servingcell change, capability information of supporting preconfiguration aresource by the target cell, or an activation time offset used tocalculate time for monitoring the specified cell.

S306: The network device determines a target cell according to themeasurement report, and controls the target cell to send a changecommand to the terminal.

The network device determines, according to the measurement report, thecandidate cell that has a largest signal measurement value or thespecified cell in the measurement report as the target cell. That is,the target cell and the specified cell are a same candidate cell.

S307: The target cell sends the change command to the terminal.

S308: The terminal determines that time for monitoring the specifiedcell does not exceed a preset time, and receives the change command.

The preset time may be timed by the terminal by using a timer, andcalculation of duration of the preset time may be implemented by addingan activation time offset to the measurement report by the terminal.

S309: The terminal performs serving cell change in the target cellaccording to the change command.

S310: The terminal sends a change completion message to the networkdevice according to content in the list of preconfigured information.

Because the list of preconfigured information includes resourceinformation of the target cell, after completing the serving cellchange, the terminal may rapidly feed back the change completion messageto the network device, which indicates that the serving cell change hasbeen completed.

S311: The network device determines that the terminal completes theserving cell change, and informs the serving cell before the change thatthe terminal completes the serving cell change.

S312: The network device sends an active set update message to theterminal.

S313: The terminal deletes the serving cell from the active setaccording to the active set update message, and adds a cell outside theactive set to the active set.

A signal measurement value of the cell that is added to the active setis greater than the signal measurement value of the serving cell.

FIG. 4 is a schematic flowchart of a third embodiment of a cell changemethod according to the present disclosure.

S41: A network device generates a measurement control message and sendsthe measurement control message to a terminal, so that the terminalmeasures a to-be-measured cell indicated in the measurement controlmessage, to obtain a signal measurement value of each cell, where theto-be-measured cell includes a candidate cell in an active set, there isat least one candidate cell, and the candidate cell preconfigures aresource for the terminal.

The signal measurement value may be an RSCP value or an Ec/No value ofpilot signal strength, or may be an accumulated value of an RSCP valueor an Ec/No value of pilot signal strength and a CIO value. A pilotsignal refers to a signal sent in a telecommunications network for apurpose of measurement and monitoring. A serving cell in the active setis a cell that provides an HS-DSCH service or an E-DCH service for theterminal, and a candidate cell is a cell that does not provide theHS-DSCH service or the E-DCH service for the terminal but establishes alink to the terminal, or a coordinated cell that provides the HS-DSCHservice or the EDCH service for the terminal but serves as a servingcell. A cell outside the active set may be a cell in a set such as amonitoring set or a detection set.

S42: The network device receives a measurement report reported by theterminal.

S43: If the measurement report is generated after the terminaldetermines, according to the signal measurement value of each cell, thatany candidate cell triggers an event 1D, the network device determines,according to the measurement report, the candidate cell that triggersthe event 1D as a target cell, and controls the target cell to send achange command to the terminal, so that the terminal uses a resource ofthe target cell to perform serving cell change in the target cellaccording to the change command.

S44: If the measurement report is generated after the terminaldetermines, according to the signal measurement value of each cell, thatany cell triggers another intra-frequency measurement event except theevent 1D, the network device determines, according to the measurementreport, a target cell from a candidate cell whose signal measurementvalue is greater than that of a serving cell, and controls the targetcell to send a change command to the terminal, so that the terminal usesa resource of the target cell to perform serving cell change in thetarget cell according to the change command.

The terminal may determine, according to the signal measurement value ofeach cell, whether any cell triggers an event 1A, an event 1B, an event1C, an event 1E, or an event 1F. If a result of the determining is yes,the terminal reports the measurement report to the network device. Thenetwork device needs to determine, according to content included in themeasurement report, the target cell to which the serving cell ischanged. In this embodiment, preferably, the serving cell triggers theevent 1B, the event 1C, or the event 1F.

If the measurement report includes the signal measurement value of eachcell, the network device needs to compare each signal measurement value,or if the measurement report does not include the signal measurementvalue of each cell, but includes only a comparison result of the signalmeasurement value of each cell, such as a descending order relationshipof the signal measurement value of each cell, the network device doesnot need to compare each signal measurement value. In this case, thenetwork device determines the target cell according to a preset rulethat is the same as that of the terminal. The preset rule may requirethat the target cell is a candidate cell that has a largest signalmeasurement value among the candidate cell whose signal measurementvalue is greater than that of the serving cell, a candidate cell thathas been in the active set for a longest time among the candidate cellwhose signal measurement value is greater than that of the serving cell,or a candidate cell that is the first to join the active set among thecandidate cell whose signal measurement value is greater than that ofthe serving cell.

If the measurement report includes cell information of only onecandidate cell whose signal measurement value is greater than that ofthe serving cell, this candidate cell is a specified cell that isdetermined by the terminal according to the preset rule, and the networkdevice directly determines this candidate cell as the target cell.

In this embodiment, while or before the network device receives themeasurement report reported by the terminal, the cell change methodfurther includes: receiving capability information reported by theterminal; determining, according to the capability information, whetherthe terminal supports enhanced serving cell change or preconfigurationof a resource by the target cell when any cell triggers the anotherintra-frequency measurement event except the event 1D; if it isdetermined that the terminal supports the enhanced serving cell changeor the preconfiguration of a resource by the target cell, performing thestep of determining, by the network device according to the measurementreport, a target cell from a candidate cell whose signal measurementvalue is greater than that of a serving cell. That is, the networkdevice may determine the target cell only after determining that theterminal can perform the enhanced serving cell change. In addition, thecapability information, reported by the terminal, of supporting theserving cell change is further included in the measurement report.

In another embodiment, while or before the network device receives themeasurement report reported by the terminal, the cell change methodfurther includes: receiving capability information reported by theterminal; determining, according to the capability information, whetherthe terminal is a single receiver or a dual receiver and whether theterminal supports enhanced serving cell change or preconfiguration of aresource by the target cell when any cell triggers the anotherintra-frequency measurement event except the event 1D; if it isdetermined that the terminal is a single receiver and supports enhancedserving cell change or the preconfiguration of a resource by the targetcell, performing the step of determining, by the network deviceaccording to the measurement report, a target cell from a candidate cellwhose signal measurement value is greater than that of a serving cell.

S45: The network device receives a change completion message that issent from the terminal in response to the change command, anddetermines, according to the change completion message, that theterminal completes the serving cell change.

S46: The network device delivers an active set update message to theterminal, so that the terminal deletes, from the active set according tothe active set update message, the serving cell before the change.

If the original serving cell, that is, the serving cell before servingcell change is performed, triggers the event 1B or the event 1F, theactive set update message is used to instruct the terminal to delete theoriginal serving cell from the active set. If the primary serving celltriggers the event 1C, the active set update message is used to instructthe terminal to delete the original serving cell from the active set,and add, to the active set, a cell of the event 1C that is outside theactive set and whose signal measurement value is greater than that ofthe primary serving cell.

S47: If a measurement report reported by the terminal is received beforethe target cell is controlled to send the change command to theterminal, the network device determines, according to the measurementreport, a new target cell from the candidate cell whose signalmeasurement value is greater than that of the serving cell, and controlsthe new target cell to send a change command to the terminal.

The terminal may periodically perform intra-frequency measurementcontrol, and therefore, it is possible that the measurement reportreported by the terminal is received again before the target cell sendsthe change command, which indicates that any cell triggers anyintra-frequency measurement event. The terminal may trigger serving cellchange after successively reporting the event 1B and the event 1D, andtriggers the event 1D after reporting the event 1B and before receivingthe change command.

The network device determines, according to the measurement report, thenew target cell from the candidate cell whose signal measurement valueis greater than that of the serving cell. The determined new target cellmay be the same as the target cell determined according to the previousmeasurement report.

In some other embodiments, the cell change method may include only S41,S42, S43, and S44, but does not include S45, S46, and S47.

In the cell change method provided in this embodiment of the presentdisclosure, a network device determines a target cell according to ameasurement report reported by a terminal, and controls the target cellto send a change command to the terminal, where the measurement reportis used to indicate that any cell triggers another intra-frequencymeasurement event except an event 1D, and a signal measurement value ofthe target cell is greater than a signal measurement value of a servingcell, thereby resolving a problem that a transmission success rate ofthe change command cannot be improved when the another intra-frequencymeasurement event except the event 1D is triggered. Because the targetcell has preconfigured a wireless resource for the terminal, signalingoverheads can be reduced, so that a serving cell change process can berapidly performed.

FIG. 5 is a schematic structural diagram of a first embodiment of aterminal according to the present disclosure. The terminal includes areceiving module 51, a measuring module 52, a monitoring module 53, areporting module 54, and a changing module 55. The receiving module 51,the measuring module 52, the monitoring module 53, the reporting module54, and the changing module 55 may be connected to each other.

The receiving module 51 is configured to receive a measurement controlmessage sent from a network device.

The measuring module 52 is configured to: measure a to-be-measured cellindicated in the measurement control message, to obtain a signalmeasurement value of each cell, and determine, according to the signalmeasurement value of each cell, whether any candidate cell triggers anevent 1D or whether any cell triggers another intra-frequencymeasurement event except the event 1D, where the to-be-measured cellincludes a candidate cell in an active set, there is at least onecandidate cell, and the candidate cell preconfigures a resource for theterminal. The signal measurement value may be an RSCP value or an Ec/Novalue of pilot signal strength, or may be an accumulated value of anRSCP value or an Ec/No value of pilot signal strength and a CIO value. Apilot signal refers to a signal sent in a telecommunications network fora purpose of measurement and monitoring. The active set includes aserving cell and a candidate cell, where the serving cell is a cell thatprovides an HS-DSCH service or an E-DCH service for the terminal, andthe candidate cell is a cell that does not provide the HS-DSCH serviceor the E-DCH service for the terminal, but establishes a link to theterminal, or a coordinated cell that provides the HS-DSCH service or theEDCH service for the terminal but serves as a serving cell. A celloutside the active set may be a cell in a set such as a monitoring setor a detection set. The resource preconfigured by the candidate cellincludes at least a channel resource, an air interface resource, and thelike.

The monitoring module 53 is configured to: when the measuring module 52determines that any candidate cell triggers the event 1D, determine thecandidate cell that triggers the event 1D as a target cell and monitorthe target cell, and configured to: when the measuring module determinesthat any cell triggers the another intra-frequency measurement eventexcept the event 1D, select, according to a preset rule, a specifiedcell from a candidate cell whose signal measurement value is greaterthan that of a serving cell, and monitor the specified cell. The anotherintra-frequency measurement event except the event 1D is a non-event 1D.Because the specified cell is selected from the candidate cell whosesignal measurement value is greater than that of the serving cell,regardless of whether the serving cell or the candidate cell triggersthe non-event 1D, it indicates that the signal measurement value of theserving cell is not the largest. For example, when the serving celltriggers an event 1B or an event 1F, it indicates that the signalmeasurement value of the serving cell is already lower than a thresholdand this situation is kept for a period of time, and for example, theterminal is increasingly far from the serving cell. For example, athreshold T and time t are set in the active set, where the threshold Tmay be a signal measurement value of a candidate cell in the active set,or may be a preset signal measurement value. As long as the signalmeasurement value of the serving cell is lower than T and this situationis kept for time t1, a trigger condition for the event 1B or the event1F is met, and a value oft is generally 640 ms. If a candidate celltriggers the event 1B or 1F, it indicates that the signal measurementvalue of the serving cell is greater than that of this candidate cell,but is still lower than those of some other candidate cells. If theserving cell triggers an event 1C, it indicates that the serving cell isa cell that has a smallest signal measurement value in the active set,and a signal measurement value of a cell outside the active set isgreater than the signal measurement value of the serving cell, and thissituation is kept for a period of time, and a value of this time is 320ms. If a candidate cell triggers the event 1C, it indicates that thiscandidate cell is a cell that has a smallest signal measurement value inthe active set, but the serving cell in this case is not a cell that hasa largest signal measurement value in the active set. In addition, whena candidate cell in the active set or a cell outside the active settriggers an event 1E, a situation in which the signal measurement valueof the candidate cell is greater than that of the serving cell may alsoexist.

The reporting module 54 is configured to report a measurement report tothe network device when the measuring module 52 determines that anycandidate cell triggers the event 1D, so that the network devicedetermines, according to the measurement report, the candidate cell thattriggers the event 1D as the target cell, and controls the target cellto send a change command to the terminal, and configured to report ameasurement report to the network device when the measuring moduledetermines that any cell triggers the another intra-frequencymeasurement event except the event 1D, so that the network devicedetermines, according to the measurement report, the target cell fromthe candidate cell whose signal measurement value is greater than thatof the serving cell, and controls the target cell to send a changecommand to the terminal. In this embodiment, the target cell is acandidate cell with best communication quality. The measurement reportmay include the signal measurement value of each cell, and then, thenetwork device needs to compare each signal measurement value, or themeasurement report does not include the signal measurement value of eachcell but includes only a comparison result of the signal measurementvalue of each cell, such as a descending order relationship of thesignal measurement value of each cell, and then, the network device doesnot need to compare each signal measurement value.

In this embodiment, there may be one specified cell or multiplespecified cells that are determined by the monitoring module 53. Ifthere is one specified cell, the target cell and the specified cell area same candidate cell. If there are multiple specified cells, the targetcell is one of the specified cells.

The receiving module 51 is further configured to receive the changecommand from the target cell.

The changing module 55 is configured to use a resource of the targetcell to perform serving cell change in the target cell according to thechange command, where there is one specified cell or multiple specifiedcells, and the target cell is the specified cell or one of the specifiedcells. Because the target cell is a monitored cell, a cell monitored bythe monitoring module 53 certainly includes the target cell, so that thechanging module 55 may receive the change command from the target cell.After the reporting module 54 reports the measurement report, thechanging module 55 cannot immediately receive the change command, butthe monitoring module 53 needs to monitor the target cell to wait forthe target cell to send the change command. In this embodiment, thechange command is sent at a physical layer. For example, the changecommand is an HS-SCCH Order. When the changing module 55 performsserving cell change, because the target cell has preconfigured theresource for the terminal, the changing module 55 does not need torequest the target cell to send information about the configuredresource, and only needs to receive the change command and rapidlycomplete the serving cell change, which reduces signaling overheads.

In the terminal provided in this embodiment, a candidate cell in anactive set preconfigures a resource for the terminal. If any celltriggers another intra-frequency measurement event except an event 1D,the terminal determines a specified cell from a candidate cell whosesignal measurement value is greater than that of a serving cell, andmonitors the specified cell. A network device determines a target cellfrom the candidate cell whose signal measurement value is greater thanthat of the serving cell, and controls the target cell to send a changecommand. The target cell is the specified cell or one of specifiedcells, a signal measurement value of the specified cell is greater thanthe signal measurement value of the serving cell, and the target cellhas preconfigured a resource for the terminal, so that a problem that atransmission success rate of the change command cannot be improved whenthe another intra-frequency measurement event except the event 1D istriggered can be resolved, and signaling overheads can be reduced, and aserving cell change process can be rapidly performed.

FIG. 6 is a schematic structural diagram of a second embodiment of aterminal according to the present disclosure. The terminal includes areceiving module 61, a measuring module 62, a monitoring module 63, areporting module 64, a changing module 65, and an updating module 66.The receiving module 61, the measuring module 62, the monitoring module63, the reporting module 64, the changing module 65, and the updating 66may be connected to each other.

The receiving module 61 is configured to receive a measurement controlmessage sent from a network device.

The measuring module 62 is configured to: measure a to-be-measuredindicated in the measurement control message, to obtain a signalmeasurement value of each cell, and determine, according to the signalmeasurement value of each cell, whether any candidate cell triggers anevent 1D or whether any cell triggers another intra-frequencymeasurement event except the event 1D, where the to-be-measured cellincludes a candidate cell in an active set, there is at least onecandidate cell, and the candidate cell preconfigures a resource for theterminal.

The monitoring module 63 is configured to: when the measuring module 62determines that any candidate cell triggers the event 1D, determine thecandidate cell that triggers the event 1D as a target cell, and monitorthe target cell, and configured to: when the measuring module determinesthat any cell triggers the another intra-frequency measurement eventexcept the event 1D, select, according to a preset rule, a specifiedcell from a candidate cell whose signal measurement value is greaterthan that of a serving cell, and monitor the specified cell.

The reporting module 64 is configured to report a measurement report tothe network device when the measuring module 62 determines that anycandidate cell triggers the event 1D, so that the network devicedetermines, according to the measurement report, the candidate cell thattriggers the event 1D as the target cell, and controls the target cellto send a change command to the terminal, and configured to report ameasurement report to the network device when the measuring module 62determines that any cell triggers the another intra-frequencymeasurement event except the event 1D, so that the network devicedetermines, according to the measurement report, a target cell from thecandidate cell whose signal measurement value is greater than that ofthe serving cell, and controls the target cell to send a change commandto the terminal. The reporting module 64 is further configured to:report capability information to the network device while or beforereporting the measurement report to the network device, so that thenetwork device determines, according to the capability information,whether the terminal supports serving cell change or preconfiguration ofa resource by the target cell when any cell triggers the anotherintra-frequency measurement event except the event 1D.

The changing module 65 is configured to: receive the change command fromthe target cell, and use a resource of the target cell to performserving cell change according to the change command, where there is onespecified cell or multiple specified cells, and the target cell is thespecified cell or one of the specified cells. The changing module 65 isfurther configured to send a change completion message in response tothe change command after completing the serving cell change, so that thenetwork device determines, according to the change completion message,that the terminal completes the serving cell change.

The receiving module 61 is further configured to receive an active setupdate message from the network device.

The updating module 66 is configured to delete, from the active setaccording to the active set update message, the serving cell before thechange. If the original serving cell, that is, the serving cell beforethe serving cell change is performed, triggers an event 1B, the activeset update message is used to instruct the updating module 66 to deletethe original serving cell from the active set. If the original servingcell triggers an event 1C, the active set update message is used toinstruct the updating module 66 to delete the original serving cell fromthe active set, and add, to the active set, a cell that is outside theactive set and whose signal measurement value is greater than that ofthe original serving cell. If the cell outside the active set triggersan event 1E, and a capacity of the active set does not reach an upperlimit, the updating module 66 may add this cell to the active setaccording to the active set update message. If the capacity of theactive set has reached the upper limit, the updating module 66 maydelete, according to the active set update message, the candidate cellthat has a smallest signal measurement value in the active set, and addthis cell outside the active set to the active set.

There are multiple implementation manners of determining the target cellby the network device. Some examples are described in detail byreference to the following situations:

In a first situation, there is one specified cell. In this case, themeasurement report includes cell information of the specified cell, sothat the network device determines the specified cell as the target cellaccording to the cell information of the specified cell. That is, whenthe monitoring module 63 determines the specified cell, the networkdevice does not know which candidate cell is determined as the specifiedcell by the monitoring module 63, and therefore the reporting module 64needs to report, in the measurement report, the cell information of thespecified cell to the network device. The cell information may be ascrambling code or a cell identifier of the specified cell.

In a second situation, there is one specified cell. In this case, themeasurement report includes the signal measurement value of each cell,so that the network device determines, according to the preset rule, thetarget cell from the candidate cell whose signal measurement value isgreater than that of the serving cell. Because the measuring module 62obtains a signal measurement value of each cell, the measuring module 62can know which candidate cell has greater signal measurement value thanthat of the serving cell, so that the monitoring module 63 may determinethe specified cell according to the preset rule.

In a third situation, there are at least two specified cells. In thiscase, the measurement report also includes a signal measurement value ofeach specified cell, so that the network device determines the targetcell from the at least two specified cells. The target cell determinedby the network device may be any one of the specified cells. Becausesignal measurement values of the specified cells are greater than thesignal measurement value of the serving cell, a signal measurement valueof the target cell is greater than the signal measurement value of theserving cell. Because the target cell is one of the specified cells, themonitoring module 63 must monitor all specified cells, and themonitoring module 63 may also monitor the target cell.

In the foregoing second and third situations, the measurement report mayalso include a comparison result of the signal measurement value. Forexample, in the second situation, the measurement report includes onlythe comparison result of the signal measurement value of each cell, butdoes not carry the signal measurement value of each cell. For example,the comparison result is a descending order relationship of all cellsaccording to the signal measurement value, and then, the network devicecan directly know, from the comparison result, which candidate cell hasa greater signal measurement value than that of the serving cell, andwhich candidate cell has a largest signal measurement value.

In the foregoing three situations, the preset rule may require that thespecified cell is a candidate cell that has a largest signal measurementvalue among the candidate cell whose signal measurement value is greaterthan that of the serving cell, a candidate cell that has been in theactive set for a longest time among the candidate cell whose signalmeasurement value is greater than that of the serving cell, or acandidate cell that is the first to join the active set among thecandidate cell whose signal measurement value is greater than that ofthe serving cell. If there are at least two cells in the active set thathave a same largest signal measurement value, the preset rule mayrequire that the specified cell is determined according to a cellsequence in the measurement report. For example, it is stipulated thatthe Nth candidate cell that has a largest signal measurement value in ameasurement result list is the specified cell, where 1≤N≤m, m is aquantity of cells in the active set. Preferably, the specified cell maybe a first candidate cell that has a largest signal measurement value,and a measurement result of this candidate cell is the first one or lastone listed in the measurement result list. Regardless of how the presetrule changes, the signal measurement value of the specified cell must begreater than the signal measurement value of the serving cell. Becausethe measurement report includes the signal measurement value of eachcell, the network device may determine the target cell according to apreset rule that is the same as that of the monitoring module 63.

Based on the foregoing three situations, the measurement furtherincludes a change request, and the change request is used to enable thenetwork device to determine whether to control the target cell to sendthe change command to the terminal.

In this embodiment, when the measuring module 62 determines that anycell triggers the another intra-frequency measurement event except theevent 1D, the reporting module 64 is further configured to construct atrigger identifier of the event 1D in the measurement report, so thatthe network device determines, according to the trigger identifier, thatthe specified cell triggers the event 1D.

In this embodiment, the changing module 65 is configured to: determinewhether the change command is received within a preset time, and whendetermining that the change command is received within the preset time,use the resource of the target cell to perform serving cell change inthe target cell according to the change command. The monitoring module63 is further configured to stop monitoring the specified cell when thechanging module 65 determines that the change command is not receivedwithin the preset time.

The reporting module 64 may further carry an activation time offset whenreporting the measurement report, and the preset time is a current CFNwhen reporting the measurement report plus the activation time offset.In wireless communication, especially in an air interfacesynchronization configuration instruction, the network device generallyneeds to add the activation time offset to signaling, and the activationtime offset specifies a frame number that causes changed configurationof the terminal to take effect. Herein, the activation time offsetindicates duration in which the monitoring module 63 monitors thespecified cell. If the measurement report does not carry the activationtime offset, the monitoring module 63 may determine, by timing with atimer, whether the preset time is exceeded.

Further, if the measuring module 62 determines, within the preset time,that any cell triggers an intra-frequency measurement event, thereporting module 64 is further configured to report a measurement reportto the network device. Further, if the target cell determined by thenetwork device according to the measurement report is a candidate cellthat has a largest signal measurement value in the active set, and thecandidate cell that has a largest signal measurement value changes whenthe reporting module 64 reports the measurement report to the networkdevice, the network device may redetermine the target cell.

FIG. 7 is a schematic structural diagram of a first embodiment of anetwork device according to the present disclosure. The network deviceincludes a sending module 71, a receiving module 72, a processing module73, a command updating module 74, and a determining module 75, and thesending module 71, the receiving module 72, the processing module 73,the command updating module 74, and the determining module 75 may beconnected to each other. In this embodiment, the network device is aradio network controller (RNC).

The sending module 71 is configured to send a measurement controlmessage to a terminal, so that the terminal measures a to-be-measuredcell indicated in the measurement control message, to obtain a signalmeasurement value of each cell, where the to-be-measured cell includes acandidate cell in an active set, there is at least one candidate cell,and the candidate cell preconfigures a resource for the terminal.

The receiving module 72 is configured to receive a measurement reportreported by the terminal and capability information reported by theterminal, where the measurement report is generated after the terminaldetermines, according to the signal measurement value of each cell, thatany candidate cell triggers an event 1D or determines that any celltriggers another intra-frequency measurement event except the event 1D.The signal measurement value may be an RSCP value or an Ec/No value ofpilot signal strength, or may be an accumulated value of an RSCP valueor an Ec/No value of pilot signal strength and a CIO value. A pilotsignal refers to a signal sent in a telecommunications network for apurpose of measurement or monitoring. The active set includes a servingcell and a candidate cell, where the serving cell is a cell thatprovides an HS-DSCH service or an E-DCH service for the terminal, andthe candidate cell is a cell that does not provide the HS-DSCH serviceor the E-DCH service for the terminal but establishes a link to theterminal, or a coordinated cell that provides the HS-DSCH service or theEDCH service for the terminal but serves as a serving cell. A celloutside the active set may be a cell in a set such as a monitoring setor a detection set. In another embodiment, the receiving module 72 mayreceive, before receiving the measurement report reported by theterminal, the capability information reported by the terminal.

The determining module 75 is configured to determine, according to thecapability information, whether the terminal supports serving cellchange or preconfiguration of a resource by a target cell, that is,enhanced serving cell change, when any cell triggers the anotherintra-frequency measurement event except the event 1D.

The processing module 73 is configured to: when the measurement reportis generated after the terminal determines, according to the signalmeasurement value of each cell, that any candidate cell triggers theevent 1D, determine, according to the measurement report, the candidatecell that triggers the event 1D as a target cell, and control the targetcell to send a change command to the terminal, so that the terminal usesa resource of the target cell to perform serving cell change in thetarget cell according to the change command, and configured to: when themeasurement report is generated after the terminal determines, accordingto the signal measurement value of each cell, that any cell triggers theanother intra-frequency measurement event except the event 1D and thedetermining module 75 determines that the terminal supports serving cellchange or the preconfiguration of a resource by the target cell,determine, according to the measurement report, a target cell from acandidate cell whose signal measurement value is greater than that ofthe serving cell, and control the target cell to send a change commandto the terminal, so that the terminal uses a resource of the target cellto perform serving cell change in the target cell according to thechange command. The processing module 73 needs to determine the targetcell according to content included in the measurement report. If themeasurement report includes the signal measurement value of each cell,the processing module 73 needs to compare the signal measurement valueof each cell to obtain a comparison result, and then determine thetarget cell according to a preset rule; if the measurement reportincludes cell information of only one candidate cell, the processingmodule 73 directly determines this candidate cell as the target cell. Inthis embodiment, the target cell is a candidate cell that has a largestsignal measurement value.

The receiving module 72 is further configured to: receive a changecompletion message that is sent from the terminal in response to thechange command. The processing module 73 is further configured todetermine, according to the change completion message, that the terminalcompletes the serving cell change.

The command updating module 74 is configured to generate an active setupdate message after the processing module 73 determines that theterminal completes the serving cell change. The sending module isconfigured to deliver the active set update message to the terminal, sothat the terminal deletes, from the active set according to the activeset update message, the serving cell before the change.

In this embodiment, if before the processing module 73 controls thetarget cell to send the change command to the terminal, the receivingmodule 72 receives the measurement report reported by the terminal, theprocessing module 73 is further configured to: receive a measurementreport again from the receiving module 72, determine, according to themeasurement report, a new target cell from the candidate cell whosesignal measurement value is greater than that of the serving cell, andcontrol the new target cell to send a change command to the terminal.

In some other embodiments, the network device includes only a sendingmodule 71, a receiving module 72, and a processing module 73, where thesending module 71 is configured to send a measurement control message toa terminal, so that the terminal measures a to-be-measured cellindicated in the measurement control message, to obtain a signalmeasurement value of each cell, where the to-be-measured cell includes acandidate cell in an active set, there is at least one candidate cell,and the candidate cell preconfigures a resource for the terminal; thereceiving module 72 is configured to receive a measurement reportreported by the terminal; the processing module 73 is configured to:when the measurement report is generated after the terminal determines,according to the signal measurement value of each cell, that anycandidate cell triggers an event 1D, determine, according to themeasurement report, the candidate cell that triggers the event 1D as atarget cell, and control the target cell to send a change command to theterminal, so that the terminal uses a resource of the target cell toperform serving cell change in the target cell according to the changecommand; and configured to: when the measurement report is generatedafter the terminal determines, according to the signal measurement valueof each cell, that any cell triggers another intra-frequency measurementevent except the event 1D, determine, according to the measurementreport, a target cell from a candidate cell whose signal measurementvalue is greater than that of a serving cell, and control the targetcell to send a change command to the terminal, so that the terminal usesa resource of the target cell to perform serving cell change in thetarget cell according to the change command.

FIG. 8 is a schematic structural diagram of a third embodiment of aterminal according to the present disclosure.

The terminal includes a processor 81, a receiver 82, a transmitter 83, arandom access memory (RAM) 84, a read only memory (ROM) 85, a bus 86,and a network interface unit 87. The processor 81 is separately coupledto the receiver 82, the transmitter 83, the RAM 84, the ROM 85, and thenetwork interface unit 87 by using the bus 86. When it is required torun the terminal, the terminal is started by using a basic input-outputsystem (BIOS) that is permanently stored in the ROM 85 or a boot loaderguiding system in an embedded system, and the terminal is guided toenter a normal working state. After the terminal enters a normal workingstate, application programs and an operating system (OS) run in the RAM84.

The receiver 82 is configured to receive a measurement control messagesent from a network device.

The processor 81 is configured to: measure a to-be-measured indicated inthe measurement control message, to obtain a signal measurement value ofeach cell, and determine, according to the signal measurement value ofeach cell, whether any candidate cell triggers an event 1D or any celltriggers another intra-frequency measurement event except the event 1D,where the to-be-measured cell includes a candidate cell in an activeset, there is at least one candidate cell, and the candidate cellpreconfigures a resource for the terminal.

The processor 81 is further configured to: when it is determined thatany candidate cell triggers the event 1D, determine a candidate cellthat triggers the event 1D as a target cell and monitor the target cell,and configured to: when it is determined that any cell triggers theanother intra-frequency measurement event except the event 1D, select,according to a preset rule, a specified cell from a candidate cell whosesignal measurement value is greater than that of a serving cell, andmonitor the specified cell. In this embodiment, the preset rule requiresthat the specified cell is a candidate cell that has a largest signalmeasurement value or a candidate cell that has been in the active setfor a longest time. If there are at least two cells in the active setthat have a same largest signal measurement value, the preset rule mayrequire that the specified cell is determined by a cell sequence in ameasurement report. For example, it is stipulated that the Nth candidatecell that has a largest signal measurement value in a measurement resultlist is the specified cell, where 1 m is a quantity of cells in theactive set. Preferably, the specified cell may be a first candidate cellthat has a largest signal measurement value, and a measurement result ofthis candidate cell is the first one or last one listed in themeasurement result list.

The transmitter 83 is configured to report a measurement report to thenetwork device when the processor 81 determines that any candidate celltriggers the event 1D, so that the network device determines, accordingto the measurement report, the candidate cell that triggers the 1D eventas the target cell, and controls the target cell to send a changecommand to the terminal, and configured to: report a measurement reportto the network device when the processor 81 determines that any celltriggers the another intra-frequency measurement event except the event1D, so that the network device determines, according to the measurementreport, a target cell from the candidate cell whose signal measurementvalue is greater than that of the serving cell and controls the targetcell to send a change command to the terminal.

The receiver 82 is configured to receive the change command from thetarget cell.

The processor 81 is further configured to use a resource of the targetcell to perform serving cell change in the target cell according to thechange command. The processor 81 is configured to: determine whether thechange command is received within a preset time, and when determiningthat the change command is received within the preset time, use theresource of the target cell to perform serving cell change in the targetcell according to the change command. The processor 81 is furtherconfigured to stop monitoring the specified cell when the receiver 82does not receive the change command within the preset time. Further, ifbefore the processor 82 receives the change command, the processor 81determines, within the preset time, that any cell triggers anintra-frequency measurement event, the transmitter 83 is furtherconfigured to report a measurement report to the network device.

In this embodiment, there is one specified cell. The measurement reportincludes cell information of the specified cell, so that the networkdevice determines the specified cell as the target cell according to thecell information of the specified cell, or the measurement reportincludes the signal measurement value of each cell, so that the networkdevice determines, according to the preset rule, the target cell fromthe candidate cell whose signal measurement value is greater than thatof the serving cell. In another embodiment, there are at least twospecified cells, and the measurement report includes signal measurementvalues of the at least two specified cells, so that the network devicedetermines the target cell from the at least two specified cells. Inaddition, the measurement report may further include a change request,so that the network device determines, according to the change request,whether to control the target cell to send the change command to theterminal.

In this embodiment, the transmitter 83 is further configured to: whenthe processor 81 determines that any cell triggers the anotherintra-frequency measurement event except the event 1D, construct atrigger identifier of the event 1D in the measurement report, so thatthe network device determines, according to the trigger identifier, thatthe specified cell triggers the event 1D. The transmitter 83 is furtherconfigured to: while or before reporting the measurement report to thenetwork device, report capability information to the network device, sothat the network device determines, according to the capabilityinformation, whether the terminal supports serving cell change orpreconfiguration of a resource by the target cell when any cell triggersthe another intra-frequency measurement event except the event 1D.

As an extension of this embodiment, the receiver 82 is furtherconfigured to receive an active set update message from the networkdevice. The processor 81 is further configured to delete, from theactive set according to the active set update message, the serving cellbefore the change.

For implementation processes of the processor 81, the receiver 82, andthe transmitter 83, refer to the cell change method and the terminal inthe foregoing embodiments, and details are not described herein again.

FIG. 9 is a schematic structural diagram of a second embodiment of anetwork device according to the present disclosure.

The network device includes a processor 91, a receiver 92, a transmitter93, a RAM 94, a ROM 95, a bus 96, and a network interface unit 97. Theprocessor 91 is separately coupled to the receiver 92, the transmitter93, the RAM 94, the ROM 95, and the network interface unit 97 by usingthe bus 96. When it is required to run the network device, the networkdevice is started by using a BIOS that is permanently stored in the ROM95 or a boot loader guiding system in an embedded system, and thenetwork device is guided to enter a normal working state. After thenetwork device enters the normal working state, application programs andan OS run in the RAM 94.

The processor 91 generates a measurement control message.

The transmitter 93 is configured to send the measurement control messageto a terminal, so that the terminal measures a to-be-measured cellindicated in the measurement control message, to obtain a signalmeasurement value of each cell, where the to-be-measured cell includes acandidate cell in an active set, there is at least one candidate cell,and the candidate cell preconfigures a resource for the terminal.

The receiver 92 is configured to receive a measurement report reportedby the terminal.

If the measurement report is generated after the terminal determines,according to the signal measurement value of each cell, that anycandidate cell triggers an event 1D, the processor 91 is configured to:determine, according to the measurement report, the candidate cell thattriggers the event 1D as a target cell, and control the target cell tosend a change command to the terminal, so that the terminal uses aresource of the target cell to perform serving cell change in the targetcell according to the change command; if the measurement report isgenerated after the terminal determines, according to the signalmeasurement value of each cell, that any cell triggers anotherintra-frequency measurement event except the event 1D, the processor 91is configured to: determine, according to the measurement report, atarget cell from a candidate cell whose signal measurement value isgreater than that of a serving cell, and control the target cell to senda change command to the terminal, so that the terminal uses a resourceof the target cell to perform serving cell change in the target cellaccording to the change command.

In this embodiment, the receiver 92 is further configured to receivecapability information reported by the terminal. The processor 91 isfurther configured to determine, according to the capabilityinformation, whether the terminal supports serving cell change orpreconfiguration of a resource by the target cell when any cell triggersthe another intra-frequency measurement event except the event 1D; andfurther configured to: when it is determined that the terminal supportsserving cell change or the preconfiguration of a resource by the targetcell, determine, according to the measurement report, the target cellfrom the candidate cell whose signal measurement value is greater thanthat of the serving cell.

In this embodiment, if the receiver 92 receives, before the processor 91controls the target cell to send the change command to the terminal, themeasurement report reported by the terminal, the processor 91 is furtherconfigured to: receive a measurement report again from the receiver 92,and determine, according to the measurement report, a new target cellfrom the candidate cell whose signal measurement value is greater thanthat of the serving cell, and control the new target cell to send achange command to the terminal.

As an extension of this embodiment, the processor 91 is furtherconfigured to generate an active set update message. The transmitter 93is further configured to delete, from the active set according to theactive set update message, the serving cell before the change.

For implementation processes of the processor 91, the receiver 92, andthe transmitter 93, refer to the cell change method and the networkdevice in the foregoing embodiments, and details are not describedherein again.

In the several embodiments provided in the present application, itshould be understood that the disclosed system, apparatus, and methodmay be implemented in other manners. For example, the describedapparatus embodiment is merely exemplary. For example, the module orunit division is merely logical function division and may be otherdivision in actual implementation. For example, a plurality of units orcomponents may be combined or integrated into another system, or somefeatures may be ignored or not performed. In addition, the displayed ordiscussed mutual couplings or direct couplings or communicationconnections may be implemented through some interfaces. The indirectcouplings or communication connections between the apparatuses or unitsmay be implemented in electronic, mechanical, or other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected according toactual needs to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of the presentapplication may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units are integratedinto one unit. The integrated unit may be implemented in a form ofhardware, or may be implemented in a form of a software functional unit.

When the integrated unit is implemented in the form of a softwarefunctional unit and sold or used as an independent product, theintegrated unit may be stored in a computer-readable storage medium.Based on such an understanding, the technical solutions of the presentapplication essentially, or the part contributing to the prior art, orall or a part of the technical solutions may be implemented in the formof a software product. The software product is stored in a storagemedium and includes several instructions for instructing a computerdevice (which may be a personal computer, a management server, or anetwork device) or a processor to perform all or a part of the steps ofthe methods described in the embodiments of the present application. Theforegoing storage medium includes: any medium that can store programcode, such as a USB flash drive, a removable hard disk, a read-onlymemory (ROM), a random access memory (RAM), a magnetic disk, or anoptical disc.

The foregoing descriptions are merely embodiments of the presentdisclosure, and the protection scope of the present application is notlimited thereto. All equivalent structure or process changes madeaccording to the content of this specification and accompanying drawingsin the present application or by directly or indirectly applying thepresent disclosure in other related technical fields shall fall withinthe protection scope of the present application.

What is claimed is:
 1. A cell change method comprising: receiving, by aterminal, a measurement control message for at least one candidate cellfrom a network device; measuring, by the terminal, a signal measurementvalue of each candidate cell of the at least one candidate cell;determing, by the terminal, according to the signal measurement value ofthe each candidate cell, whether any candidate cell of the at least onecandidate cell triggers a first event that a pilot signal strength of acell is greater than that of a current serving cell; when the terminaldetermines a candidate cell of the at least one candidate cell triggersa first intra-frequency measurement event that a pilot signal strengthof a cell is greater than that of a current serving cell, determiningthe candidate cell of the at least one candidate cell that triggers thefirst event as a target cell; and reporting a first measurement reportof the target cell to the network device for determining, according tothe first measurement report, the candidate cell that triggers the firstevent as the target cell, and controlling the target cell to send achange command to the terminal; or, when the terminal determines acandidate cell of the at least one candidate cell triggers anintra-frequency measurement event except the first event, selecting,according to a preset rule, a cell from at least one candidate cellwhose signal measurement value is greater than that of the serving cellas a target cell; and reporting a second measurement report of theselected cell to the network device for determining, according to thesecond measurement report, the target cell from the at least onecandidate cell whose signal measurement value is greater than that ofthe serving cell, and controlling the target cell to send a changecommand to the terminal; and receiving, by the terminal, the changecommand from the target cell; and performing by using a preconfiguredresource of the target cell, by the terminal, a serving cell change inthe target cell according to the change command.
 2. The change methodaccording to claim 1, wherein the second measurement report comprisescell information of the selected cell, so that the network devicedetermines the selected cell to be the target cell according to the cellinformation of the selected cell.
 3. The change method according toclaim 1, wherein there are at least two selected cells, and the secondmeasurement report comprises signal measurement values of the at leasttwo selected cells, so that the network device determines the targetcell from the at least two selected cells.
 4. The change methodaccording to claim 1, wherein the second measurement report furthercomprises a change request, so that the network device determines,according to the change request, whether to control the target cell tosend the change command to the terminal.
 5. The change method accordingto claim 1, wherein the preset rule comprises a requirement that theselected cell is a candidate cell with a largest signal measurementvalue.
 6. The change method according to claim 1, wherein when there areat least two candidate cells with a largest signal measurement value,the preset rule comprises a requirement that the selected cell is acandidate cell that is listed in a preset location of the secondmeasurement report and has a largest signal measurement value.
 7. Thechange method according to claim 1, wherein the preset rule comprises arequirement that the selected cells is a candidate cell that is thefirst one or last one listed in the second measurement report and has alargest signal measurement value.
 8. The change method according toclaim 1, wherein during or before reporting the second measurementreport to the network device, the change method further comprises:reporting, by the terminal, capability information to the network devicefor determing, according to the capability information, whether theterminal supports the serving cell change or preconfiguration of aresource by the target cell when any cell triggers the anotherintra-frequency measurement event except the first event.
 9. The changemethod according to claim 1, wherein the change method furthercomprises: receiving, by the terminal, an update message from thenetwork device, and deleting, by the terminal, from the at least onecandidate cell according to the update message, a serving cell beforethe serving cell change is made in response to the change command. 10.An apparatus comprising: at leaset one processor and a non-transitorycomputer readable storage medium, wherein the non-transitory computerreadable storage medium comprises a program which, when executed by theat leaset one processor, causes the at leaset one processor configuredto: receive a measurement control message for at least one candidatecell from a network device; measure a signal measurement value of eachcandidate cell of the at least one candidate cell; determine, accordingto the signal measurement value of the each candidate cell, whether anycandidate cell of the at least one candidate cell triggers a first eventthat a pilot signal strength of a cell is greater than that of a currentserving cell; when determining a candidate cell of the at least onecandidate cell triggers a first intra-frequency measurement event that apilot signal strength of a cell is greater than that of a currentserving cell, determine the candidate cell of the at least one candidatecell that triggers the first event as a target cell; and report a firstmeasurement report of the target cell to the network device fordetermining, according to the first measurement report, the candidatecell that triggers the first event as the target cell, and controllingthe target cell to send a change command to a terminal; or, whendetermining a candidate cell of the at least one candidate cell triggersan intra-frequency measurement event except the first event, select,according to a preset rule, a cell from at least one candidate cellwhose signal measurement value is greater than that of the serving cellas a target cell; and report a second measurement report of the selectedcell to the network device for determining, according to the secondmeasurement report, the target cell from the at least one candidate cellwhose signal measurement value is greater than that of the serving cell,and controlling the target cell to send a change command to a terminal;and receive the change command from the target cell; and perform, byusing a preconfigured resource of the target cell, a serving cell changein the target cell according to the change command.
 11. The apparatusaccording to claim 10, wherein the second measurement report comprisescell information of the selected cell, so that the network devicedetermines the selected cell to be the target cell according to the cellinformation of the selected cell.
 12. The apparatus according to claim10, wherein there are at least two selected cells, and the secondmeasurement report comprises signal measurement values of the at leasttwo selected cells, so that the network device determines the targetcell from the at least two selected cells.
 13. The apparatus accordingto claim 10, wherein the second measurement report further comprises achange request, so that the network device determines, according to thechange request, whether to control the target cell to send the changecommand to the terminal.
 14. The apparatus according to claim 10,wherein the preset rule comprises a requirement that the selected cellis a candidate cell with a largest signal measurement value.
 15. Theapparatus according to claim 10, wherein when there are at least twocandidate cells with a largest signal measurement value, the preset rulecomprises a requirement that the selected cell is a candidate cell thatis listed in a preset location of the second measurement report and hasa largest signal measurement value.
 16. The apparatus according to claim10, wherein the preset rule comprises a requirement that the selectedcells is a candidate cell that is the first one or last one listed inthe second measurement report and has a largest signal measurementvalue.
 17. The apparatus according to claim 10, wherein the at leasetone processor is further configured to, during or before reporting thesecond measurement report to the network device, report capabilityinformation to the network device for determing, according to thecapability information, whether the terminal supports the serving cellchange or preconfiguration of a resource by the target cell when anycell triggers the another intra-frequency measurement event except thefirst event.
 18. The apparatus according to claim 10, wherein the atleaset one processor is further configured to receive an update messagefrom the network device, and delete from the at least one candidate cellaccording to the update message, a serving cell before the serving cellchange is made in response to the change command.
 19. An apparatuscomprising: a receiver, configured to receive a measurement controlmessage for at least one candidate cell from a network device and achange command from a target cell; and a processor, configured tomeasure a signal measurement value of each candidate cell of the atleast one candidate cell; determine, according to the signal measurementvalue of the each candidate cell, whether any candidate cell of the atleast one candidate cell triggers a first event that a pilot signalstrength of a cell is greater than that of a current serving cell;wherein the processor is further configured to, when determining acandidate cell of the at least one candidate cell triggers a firstintra-frequency measurement event that a pilot signal strength of a cellis greater than that of a current serving cell, determine the candidatecell of the at least one candidate cell that triggers the first event asthe target cell; or, wherein the processor is further configured to,when determining a candidate cell of the at least one candidate celltriggers an intra-frequency measurement event except the first event,select, according to a preset rule, a cell from at least one candidatecell whose signal measurement value is greater than that of the servingcell as the target cell; wherein the processor is further configured toperform, by using a preconfigured resource of the target cell, a servingcell change in the target cell according to the change command; whereinthe apparatus further comprises: a transmitte, configured to report afirst measurement report of the target cell to the network device fordetermining, according to the first measurement report, the candidatecell that triggers the first event as the target cell, and controllingthe target cell to send the change command to a terminal; or report asecond measurement report of the selected cell to the network device fordetermining, according to the second measurement report, the target cellfrom the at least one candidate cell whose signal measurement value isgreater than that of the serving cell, and controlling the target cellto send the change command to a terminal.
 20. The apparatus according toclaim 19, wherein the preset rule comprises a requirement that theselected cell is a candidate cell with a largest signal measurementvalue.
 21. The apparatus according to claim 19, wherein the transmitteris further configured to, during or before reporting the secondmeasurement report to the network device, report capability informationto the network device for determing, according to the capabilityinformation, whether the terminal supports the serving cell change orpreconfiguration of a resource by the target cell when any cell triggersthe another intra-frequency measurement event except the first event.22. The apparatus according to claim 19, wherein the receiver is furtherconfigured to receive an update message from the network device, and theprocessor is further configured to delete from the at least onecandidate cell according to the update message, a serving cell beforethe serving cell change is made in response to the change command.
 23. Acell change method comprising: sending, by a network device, ameasurement control message to a terminal, enabling the terminal toobtain a signal measurement value of each candidate cell; and receiving,by the network devicer, a first or second measurement report from theterminal, wherein (a) the first measurement report indicates that acandidate cell triggers a first event that a pilot signal strength of acell is greater than that of a current serving cell and (b) the secondmeasurement report indicates that a candidate cell triggers anintra-frequency measurement event other than the first event; whereinthe method further comprises: a) determining, by the network devicer,according to the first measurement report, the candidate cell thattriggers the first event as a target cell, and control the target cellto send a change command to the terminal, which is intended to enablethe terminal to perform, by using a resource of the target cell, aserving cell change in the target cell according to the change command;or b) determining, by the network devicer, according to the secondmeasurement report, a target cell from at least one candidate cell whosesignal measurement value is greater than that of the serving cell, andcontrol the target cell to send a change command to the terminal, whichis intended to enable the terminal to perform, by using a resource ofthe target cell, the serving cell change in the target cell according tothe change command.
 24. The method according to claim 23, wherein themethod further comprises: receiving, by the network device, capabilityinformation reported by the terminal; determine, by the network device,according to the capability information, whether the terminal supportsthe serving cell change or preconfiguration of a resource by the targetcell when any cell triggers the intra-frequency measurement event exceptthe first event, and when it is determined that the terminal supportsthe serving cell change or the preconfiguration of a resource by thetarget cell, determining, according to the measurement report, thetarget cell from the at least one candidate cell whose signalmeasurement value is greater than that of the serving cell.
 25. Themethod according to claim 23, wherein when receiving the measurementreport from the terminal, before controlling the target cell to send thechange command to the terminal, the method further comprises: receiving,by the network device, the measurement report again from the terminal;determining, by the network device, according to the measurement report,a new target cell from the at least one candidate cell whose signalmeasurement value is greater than that of the serving cell; andcontrolling, by the network device, the new target cell to send a newchange command to the terminal.
 26. The method according to claim 23,wherein the method further comprises: sending, by the network device, anupdate message to the terminal for deleting, from the at least onecandidate cell according to the update message, the serving cell beforethe change.